On 2020/7/31 下午2:55, Zhu Lingshan wrote:

+static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
+{
+	struct vhost_virtqueue *vq = &v->vqs[qid];
+	const struct vdpa_config_ops *ops = v->vdpa->config;
+	struct vdpa_device *vdpa = v->vdpa;
+	int ret, irq;
+
+	spin_lock(&vq->call_ctx.ctx_lock);
+	irq = ops->get_vq_irq(vdpa, qid);

Btw, this assumes that get_vq_irq is mandatory. This looks wrong since 
there's no guarantee that the vDPA device driver can see irq. And this 
break vdpa simulator.

Let's add a check and make it optional by document this assumption in 
the vdpa.h.

Thanks

+	if (!vq->call_ctx.ctx || irq < 0) {
+		spin_unlock(&vq->call_ctx.ctx_lock);
+		return;
+	}
+